Ceramic Industry

Case Study: Flexibility in Filling

April 1, 2001
A mobile bulk bag filler is reducing downtime and increasing filling accuracy for Johnson Matthey’s new Jacksonville, Fla., facility.

The mobile bulk bag filler connects to the silo through a rotary flow control valve mounted on the fill head. Frame-mounted control panel and forklift sleeves permit easy moving of the filler. A dust collection line connects from the fill head to the plant dust collection system.
As one of the world’s largest suppliers of color and associated coating materials, Johnson Matthey Structural Ceramics sells zircon as an alloying agent in ceramic compounds. One of the keys to its new Jacksonville, Fla., plant is its flexible material handling capabilities. Two ball mills crush 100-mesh, high bulk density (170 lbs/cubic foot) zircon material, processed from Florida mines, to four grades, which are loaded into four 50-ton silos. Three skid-mounted bag-packing machines, under gain-in-weight control, fill different size 50-lb, multi-wall paper bags. But perhaps the most important part of the materials handling operation is the mobile bulk bag filler,* also under gain-in-weight control, which fills bulk bags weighing between 1000 to 4000 lbs. To bag each grade, the bag packing machines and bulk bag filler move by forklift from one silo to the next up to three times a month.

An operator inputs settings on a frame-mounted control panel. Load cells transmit gain-in-weight information to the controller, which actuates a rotary valve, filling bags to ±1% accuracy.

Cutting Down on Labor

The mobility of the bulk bag filler gives operators eight hours more per month to pack bags instead of move machinery. Dan Rooney, Johnson Matthey Structural Ceramics’ general manager, says he designed the flexible packaging system “to avoid the downtime problems experienced at similar plants.”

In a conventional installation, relocating stationary bag packing machines or bulk bag fillers is a three-hour affair. Plant electricians and mechanics, under supervision of the packing machine operators, disconnect floor fastener plates, wiring and pneumatic lines, move the machine, bolt it down, and reconnect the wiring and pneumatics. The operator may also need to recalibrate the bulk bag filler’s load cells and weigh-batch controller.

The mobile bulk bag filler, on the other hand, features forklift sleeves, an 8-in. diameter rotary flow control valve mounted on the fill head to control flow from the silos, and a frame-mounted control panel that requires no calibration between moves.

“The system provides more automation and less manual input,” Rooney says.

When moving the bulk bag filler, the operator unplugs its power line from the station’s 440-volt outlet and disconnects the pneumatic line. A forklift moves the filler to the next station, where the operator plugs the power line into the station’s 440-volt outlet and connects to a pneumatic line suspended from the ceiling. The transfer takes approximately five minutes.

Strengthening the 60-in.-wide by 126-in.-tall bulk bag filler for its frequent moves are twin 5-in. tubular centerposts and an additional rear post.

In operation, the load cells and system controller remain unaffected by the filler’s automated vibratory densification/deaeration bed, which stabilizes and settles the material to fully fill the bag. Inflatable air mounts located at the bottom of the frame raise the bed, isolating the frame from vibration.

Accurate Filling and Dust Control

Gain-in-weight controls automatically turn the rotary valve on and off to fill bulk bags to ±1% accuracy. Load cells located under the bulk bag filler frame transmit gain-in-weight information to the system controller proportional to the load of bag and filler. Once the accurate fill weight has been loaded, the controller switches off the rotary valve.

To minimize dust, the fill head is equipped with an inflatable rubber membrane, facilitating a rapid, dust-tight seal to the bag spout. As an added measure, Rooney plans to connect the fill head’s dust collection port to the plant's dust collection system.

Overall, the mobile bulk bag filler is helping Johnson Matthey achieve its goals of accurate weighing with an efficient production schedule. “The plant gets the flexibility it needs, and customers get accurate weights as they purchase zircon by the pound,” Rooney says.

For More Information

For more information about the new Johnson Matthey plant, contact Dan Rooney, 11400 New Berlin Road, Jacksonville, FL 32226; (904) 751-2828; fax (904) 751-6828. Or see “JM Plans for Bright Future,” CI October 2000 (in the “Editorial Archives” section.)

For more information about the flexible bulk bag filler, contact Flexicon Corp., 1375 Stryker’s Road, P.O. Box 5269, Phillipsburg, NJ 08865-5269; (888) 353-9426; fax (908) 859-4820; or e-mail sales@flexicon.com.